Merge branch 'x86-uaccess-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 uaccess changes from Ingo Molnar:
 "A single change that micro-optimizes __copy_*_user_inatomic(), used by
  the futex code"

* 'x86-uaccess-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Add 1/2/4/8 byte optimization to 64bit __copy_{from,to}_user_inatomic

1 files changed, 18 insertions, 6 deletions

diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
index 0acae710fa00..190413d0de57 100644
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -49,11 +49,10 @@ __must_check unsigned long
 copy_in_user(void __user *to, const void __user *from, unsigned len);
 
 static __always_inline __must_check
-int __copy_from_user(void *dst, const void __user *src, unsigned size)
+int __copy_from_user_nocheck(void *dst, const void __user *src, unsigned size)
 {
         int ret = 0;
 
-        might_fault();
         if (!__builtin_constant_p(size))
                 return copy_user_generic(dst, (__force void *)src, size);
         switch (size) {
@@ -93,11 +92,17 @@ int __copy_from_user(void *dst, const void __user *src, unsigned size)
 }
 
 static __always_inline __must_check
-int __copy_to_user(void __user *dst, const void *src, unsigned size)
+int __copy_from_user(void *dst, const void __user *src, unsigned size)
+{
+        might_fault();
+        return __copy_from_user_nocheck(dst, src, size);
+}
+
+static __always_inline __must_check
+int __copy_to_user_nocheck(void __user *dst, const void *src, unsigned size)
 {
         int ret = 0;
 
-        might_fault();
         if (!__builtin_constant_p(size))
                 return copy_user_generic((__force void *)dst, src, size);
         switch (size) {
@@ -137,6 +142,13 @@ int __copy_to_user(void __user *dst, const void *src, unsigned size)
 }
 
 static __always_inline __must_check
+int __copy_to_user(void __user *dst, const void *src, unsigned size)
+{
+        might_fault();
+        return __copy_to_user_nocheck(dst, src, size);
+}
+
+static __always_inline __must_check
 int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
 {
         int ret = 0;
@@ -192,13 +204,13 @@ int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
 static __must_check __always_inline int
 __copy_from_user_inatomic(void *dst, const void __user *src, unsigned size)
 {
-        return copy_user_generic(dst, (__force const void *)src, size);
+        return __copy_from_user_nocheck(dst, (__force const void *)src, size);
 }
 
 static __must_check __always_inline int
 __copy_to_user_inatomic(void __user *dst, const void *src, unsigned size)
 {
-        return copy_user_generic((__force void *)dst, src, size);
+        return __copy_to_user_nocheck((__force void *)dst, src, size);
 }
 
 extern long __copy_user_nocache(void *dst, const void __user *src,